| District of Colorado area codes: 720 | |
|---|---|
| Country | United States |
| State/Province | Colorado |
| Major City | Denver |
| Time Zone | Mountain |
| Prefix | County | Primary City | Company |
|---|---|---|---|
| 720-363 | Jefferson | Denver, CO | Sprint Spectrum L.p. |
| 720-364 | Denver | Denver, CO | Leap Wireless Intl DBA Cricket Comm |
| 720-365 | Jefferson | Denver, CO | Leap Wireless Intl DBA Cricket Comm |
| 720-366 | Jefferson | Denver, CO | Leap Wireless Intl DBA Cricket Comm |
| 720-367 | Arapahoe | Englewood, CO | Xo Colorado |
| 720-368 | Arapahoe | Englewood, CO | Xo Colorado |
| 720-369 | Jefferson | Denver, CO | New Cingular Wireless PCS |
| 720-370 | Denver | Denver, CO | Bandwidth.com Clec |
| 720-371 | Jefferson | Denver, CO | Sprint Spectrum L.p. |
| 720-372 | Arapahoe | Aurora, CO | T-mobile Usa |
| 720-373 | Jefferson | Denver, CO | Sprint Spectrum L.p. |
| 720-374 | Denver | Denver, CO | Qwest Corporation |
| 720-375 | Jefferson | Denver, CO | Commnet Wireless |
| 720-376 | Denver | Denver, CO | Eschelon Telecom Of Colorado |
| 720-377 | Denver | Denver, CO | Xo Colorado |
| 720-378 | Boulder | Longmont, CO | New Cingular Wireless PCS |
| 720-379 | Denver | Denver, CO | Icg Telecom Group |
| 720-380 | Jefferson | Denver, CO | Sprint Spectrum L.p. |
| 720-381 | Jefferson | Denver, CO | Comcast Phone Of Colorado |
| 720-382 | Adams | Denver, CO | Eschelon Telecom Of Colorado |
There are 519 prefixes, In the code area, the major cities are Arvada, CO;Aurora, CO;Boulder, CO;Brighton, CO;Bro. The major city is Denver.